Atrial myxoma - Skin
Cutaneous manifestations of atrial myxomas are non-specific and can be classified into embolic cutaneous signs, non-embolic signs associated with autoimmune symptoms, and cutaneous signs of a complex syndrome. Solitary cutaneous myxomas have also been described, but are thought to be distinct entities from cardiac myxomas.
75% to 80% of cardiac myxomas are localized in the left atrium, 15% to 20% are localized in the right atrium, and 10% are either biatrial or in the ventricles. Myxomas most commonly develop from the interatrial septum but can also originate from the posterior and anterior atrial walls or the atrial appendage.
Dyspnea, recurrent pulmonary edema, and right heart failure may suggest obstructed filling of the right or left ventricles. Auscultatory findings include arrhythmias such as atrial fibrillation and systolic and diastolic murmurs depending on tumor location and mobility. Right atrial involvement may present with pericardial friction rub, and left atrial tumors present with loud and widely split S1. Large myxomas obstructing the mitral or tricuspid valve may lead to syncope and sudden death.
Constitutional manifestations include fever, fatigue, erythematous rash, arthralgia, myalgia, and weight loss. Raynaud's phenomenon, polymyositis, hepatic dysfunction, and hyperglobulinemia may also occur. These symptoms are attributed to an autoimmune response or secondary infection from the tumor.
Most cases arise sporadically. Familial cases have been postulated as autosomal dominant inheritance with a variable phenotype and are associated with the occurrence of multiple and atypical tumors. Complex familial tumors are part of a rare condition called the Carney complex. Carney complex may manifest with adrenocortical involvement, pituitary-related symptoms, abnormal pigmentation, or multiple neoplasias in the skin, thyroid, testicles, breast, and neural systems. Heterozygous mutation in the PRKAR1A gene, a protein kinase A regulatory subunit-1-alpha gene, on chromosome 17q22-24 has been linked to cases of intracardiac myxoma and to Carney complex type 1. Carney complex type 2 involves a locus at chromosome 2p16, although the gene responsible remains unknown.
Cardiac myxomas can grow rather quickly. Recurrence is thought to be due to inadequate resection, multicentric growth, inheritance, or metastasis and usually happens during the first 4 years post-excision. Sporadic cases almost never recur, while incidence of recurrence for familial cases, Carney complex, and multiple myxomas are 10%, 22%, and 33%, respectively.
D15.1 – Benign neoplasm of heart
233854003 – Atrial myxoma
- Livedo reticularis
- Pigmented purpuric dermatosis (see capillaritis)
- Benign patterned centrofacial lentiginosis
- Malignant melanoma
- Melanocytic nevi
- Ephelides (freckles)
Benign primary cardiac tumors:
- Papillary fibroelastomas – Second most common benign cardiac tumor; occurs predominately in elderly patients (>80 years old). Usually less than 1 cm in diameter, sessile pedunculated tumors attached to the mitral valve or semilunar valves; occurs exclusively on endocardium.
- Rhabdomyomas – Most common cardiac tumor in children; often multiple masses located in the ventricular myocardium; 50% of cases are associated with tuberous sclerosis.
- Fibromas – Congenital tumors seen in children. Usually solitary, fibrous, and calcified; located in the myocardium.
- Hemangiomas – Highly vascularized.
- Lipomas – Encapsulated tumors usually originating from the epicardium.
- Atrioventricular node tumor – Located at the base of the atrial septum.
- Angiosarcoma – Highly invasive; usually with evidence of lung, brain, and/or liver metastasis upon diagnosis.
- Rhabdomyosarcoma – Usually diagnosed in children; highly aggressive and may occur in any heart chamber.
- Osteosarcoma – Bulky, sessile tumors usually located in the left atrium.
- Leiomyosarcoma – Highly invasive; sessile masses with mucoid surface.
- Lymphoma – Associated with lymphoproliferative conditions such as AIDS and in immunocompromised patients.
Right atrial masses – Prominent eustachian valve; aneurysms of the interatrial septum.
Cushing's syndrome with primary pigmented nodular adrenocortical disease (PPNAD)
Cardiac myxomas should always be considered as a differential in cases of pulmonary embolism and diagnosed definitively by histological evaluation.